can anyone point me to the upgrades over the years GM made to the 60 degree? AS far as sensors, wiring, ports, block info. I am looking for a timeline of changes, if it exists.
Thanks

 

pics of the 3.1 vs. 2.8 intake and plenum would be awesome. 3.4 intake as well. i found several posts, but the pics didnt work.

 

I've got pictures of the 2.8 vs the 3.4 lower intake if you are interested.

 

2.8 3.1L intakes are almost the exact same.

Heres a 3.1L plentum.

Upper



Middle


Gray one in the middle on this pic is the lower intake.

 

http://60degreev6.com/content.php/29...V6-Family-Tree

 

2.8 and 3.1 use the same lower manifold... 3.1 has plugs in the holes for the cold start injector and CSI switch (probably a different part number because of the plugs...). The 3.4 got a revised manifold with neither hole or any provisions for the CSI system altogether.

The lower plenum (the part the fuel rail bolts to) may or may not be the same part in the 2.8 or 3.1. If someone with either or both could confirm?

3.1 fuel rail is the same as the 2.8 with the exception of the CSI fitting delete (which resulted in another P/N change). And the fuel lines connecting to the rails are different.

Upper plenums and throttle bodies are different due to revision of the idle air intake system, and as a result, changes to the emissions control vacuum circuits.

2.8 and 3.1 used the same valve covers, except some (possibly most) 2.8 covers were SILVER. Every 3.1 valve cover I've seen is BLACK. Not oily, either, painted. Unless you're talking the 2.8 in the Fiero, which got completely different covers.

Not sure about the 88-9 2.8s, but I do know that the 3.1 has a plug in the port on the oil filter adapter where the 2.8's oil pressure gauge/light sender would go as it used a 3-wire sending unit that works both the gauge and fuel pump.

Most auto 2.8s didn't get the AIR system as long as they were automatic. Except in the cases of the recalled 86-87 cars that had revised PROMs for cold running issues, which may have had it added. All 3.1s got it due to new standards.

Whatever year the 2.8 was switched to serpentine belt drive was the year that the water pump was changed to turn in the opposite direction. And I think that may have been the year that the alternator was changed from the SI to the CS, but I'm not sure on that.

Everything internal to the long block is on the 60degree site.